• 文献标题:   High-speed and broadband terahertz wave modulators based on large-area graphene field-effect transistors
  • 文献类型:   Article
  • 作  者:   MAO Q, WEN QY, TIAN W, WEN TL, CHEN Z, YANG QH, ZHANG HW
  • 作者关键词:  
  • 出版物名称:   OPTICS LETTERS
  • ISSN:   0146-9592 EI 1539-4794
  • 通讯作者地址:   Univ Elect Sci Technol China
  • 被引频次:   49
  • DOI:   10.1364/OL.39.005649
  • 出版年:   2014

▎ 摘  要

We present a broadband terahertz wave modulator with improved modulation depth and switch speed by cautiously selecting the gate dielectric materials in a large-area graphene-based field-effect transistor (GFET). An ultrathin Al2O3 film (similar to 60 nm) is deposited by an atomic-layer-deposition technique as a high-k gate dielectric layer, which reduces the Coulomb impurity scattering and cavity effect, and thus greatly improves the modulation performance. Our modulator has achieved a modulation depth of 22% and modulation speed of 170 kHz in a frequency range from 0.4 to 1.5 THz, which is a large improvement in comparison to its predecessor of SiO2-based GFET. (C) 2014 Optical Society of America